Frequency-selective single photon detection using a double quantum dot

Understand

We use a double quantum dot as a frequency-tunable on-chip microwave detector to investigate the radiation from electron shot-noise in a near-by quantum point contact.

• The device is realized by monitoring the inelastic tunneling of electrons between the quantum dots due to photon absorption.
• The frequency of the absorbed radiation is set by the energy separation between the dots, which is easily tuned with gate voltages.
• Using time-resolved charge detection techniques, we can directly relate the detection of a tunneling electron to the absorption of a single photon.